Ethnic minorities could be disenfranchised by new rules requiring voters to carry identification to the polls, the government has been warned as a former minister likened immigration policy to the rhetoric of Enoch Powell.

As more cases of personal tragedy among the so-called Windrush generation emerged, ministers appearing on Sunday politics programmes were forced to defend Home Secretary Amber Rudd from cross-party calls for her resignation.

Theresa May has said the victims of the government’s ‘hostile environment’ policy, which has seen dozens of people legally resident in the UK for decades wrongly threatened with deportation and denied public services, will receive compensation.

But the Justice Secretary defended requirements for foreigners to prove their immigration status in order to access the NHS, insisting that while he was “ashamed” of the way Windrush immigrants had been treated, “the central policy is right”.

A leaked letter from the Equalities and Human Rights Commission has warned ministers that the government risks being sued for discriminating against ethnic minority communities over new voter ID rules being trialled ahead of local elections in England on 3 May.

In three local authorities, people will be asked to produce documents proving their identity in order to cast their vote. The letter, sent to Cabinet Office minister David Lidington, warns that legal residents who may not have a passport or driving licence could be disenfranchised.

The Electoral Commission says voter fraud is very limited in the UK. Labour leader Jeremy Corbyn called the plans “disgraceful” and said they would create “the same hostile environment all over again”.

There were calls yesterday for Ms Rudd to resign from Mr Corbyn and senior shadow cabinet members John McDonnell and Emily Thornberry, as well as SNP Westminster leader Ian Blackford.

Following the 50th anniversary of Powell’s infamous ‘Rivers of Blood’ speech last week, the former Tory cabinet minister Baroness Warsi said: “My grandfather arrived here in the fifties and my parents arrived here in the sixties, and I know growing up the paranoia that they had about paperwork and passports.

“I think that came from a deep-rooted concern amongst other things from the rhetoric we were hearing from the likes of Enoch Powell that there may come a day when they would be told to leave.”